A known rotary electric machine including plural bus bars is disclosed, for example, in JP2015-97450A which is hereinafter referred to as Reference 1. In addition, a known rotary electric machine including concentrated winding coils is disclosed, for example, in JP2013-223322A which is hereinafter referred to as Reference 2.
The rotary electric machine disclosed in Reference 1 includes a stator where plural stator pieces are annularly disposed in a circumferential direction relative to an axis of the stator and a rotor disposed coaxially with the stator and facing the stator. The stator pieces are constituted by plural split cores including projecting teeth at which phase coils (windings) are wound respectively, the phase coils corresponding to W-phase coils, V-phase coils and U-phase coils. The stator includes the plural bus bars, specifically, a W-phase bus bar, a V-phase bus bar, a U-phase bus bar and a common bus bar, which supply an electric power to the corresponding phase coils and which are connected to the corresponding stator pieces for the respective phases so as to maintain an annular arrangement of the split cores. Each of the W-phase bus bar, the V-phase bus bar, the U-phase bus bar and the common bus bar is formed in an annular plate. The W-phase bus bar, the V-phase bus bar and the U-phase bus bar are disposed at positions corresponding to the W-phase coils, the V-phase coils and the U-phase coils, respectively.
The rotary electric machine disclosed in Reference 2 includes a stator core including twelve teeth. The concentrated winding coils are constituted as three-phase alternating current windings in a state where the four concentrated winding coils are connected in parallel to one another for each phase. The concentrated winding coil wound at each of the teeth includes a coil terminal at each of a winding start portion and a winding end portion. That is, the two coil terminals are provided at each of the teeth. As a result, the twenty-four coil terminals in total are provided at the rotary electric machine. In addition, the rotary electric machine includes three bus bars each of which includes four coil connection terminals and one bus bar for a neutral point connection including twelve coil connection terminals. In the rotary electric machine disclosed in Reference 2, the coil terminals of the concentrated winding coils and the coil connection terminals of the bus bars are connected by welding to thereby achieve a Y-connection of the concentrated winding coils.
According to the rotary electric machine disclosed in Reference 1, in a case where each of the bus bars is assembled on the stator, the bus bar may be assembled in a wrong phase (wrong rotation direction position), which may lead to a connection failure between the bus bar and the phase coils. According to the rotary electric machine disclosed in Reference 2, the coil terminals (terminal members) are provided at the winding start portion and the winding end portion of each of the concentrated winding coils wound at the teeth. Thus, the two terminal members are necessary for each of the concentrated winding coils wound at the teeth. In a case of assembling the rotary electric machine, the number of welding for connecting the concentrated winding coils and the terminal members is required for the number of the terminal members. As a result, the number of welding (number of manufacturing processes) may be relatively large.
A need thus exists for a rotary electric machine which is not susceptible to the drawback mentioned above.